1. Field of the Invention
The present invention relates to a display device, and more particularly to a liquid crystal display device which can prevent the occurrence of flickers or the like due to imbalance of capacitance when a size of a pixel is changed for every color such that the whole screen acquires predetermined chromaticity.
2. Description of the Related Art
A liquid crystal display device includes a TFT substrate on which pixel electrodes, thin film transistors (TFT) and the like are formed in a matrix array, a counter substrate which is arranged to face the TFT substrate in an opposed manner and forms color filters or the like thereon at positions corresponding to the pixel electrodes of the TFT substrate, and liquid crystal which is sandwiched between the TFT substrate and the counter substrate. Here, an image is formed by controlling transmissivity of light of the pixel for every pixel by changing the behavior of the liquid crystal molecules.
In general, the liquid crystal display device is formed of pixels of respective colors consisting of red, green and blue, and the respective pixels have the same size. However, depending on a usage of the liquid crystal display device, there may be a case where the whole screen is requested to have particular hue. Alternatively, when the sizes of the pixels of red, green and blue are set equal, there may be a case that complete white cannot be obtained in white display, and color of the screen is deviated to particular hue. In such a case, the correction of hue is required. For this end, there has been proposed a technique which makes a size of a pixel of red, green or blue different from pixels of other colors.
JP-A-2007-17619 (patent document 1) describes the constitution of an IPS (In Plane Switching)-type liquid crystal display device in which transmissivity of a pixel of red, green or blue is changed for adjusting a color tone of a screen.
JP-A-2000-162627 (patent document 2) describes the constitution of a liquid crystal display device where a size of a blue pixel is set larger than a size of a red pixel or a green pixel, and to cope with a drawback caused by a change of capacitance for every pixel when the number of electrodes of blue pixels is increased, a rate between a gate/source capacitance (parasitic capacitance) and the whole capacitance of a TFT is set to a constant value.
JP-A-7-325287 (patent document 3) discloses the constitution of a liquid crystal display device which changes auxiliary capacitance for preventing an image from being influenced by a change of capacitance when a layer thickness of liquid crystal differs depending on a location.